Horizontal decanter centrifuges are capable of processing large quantities of liquid and removing suspended solids from the liquid. These types of centrifuges are used in many different industries, but they find especially useful application in the oil and gas industry in the purification of drilling fluid, referred to as drilling mud.
In the purification of drilling fluid, huge quantities of sand and rock, including cuttings from the drilling process, are processed through one or more centrifugal separators. The mixture of solids and liquid enters a centrifuge and proceeds into a conical housing which turns at high speed, for example 3,000 rpm. At this speed, heavier solids migrate out to the inside surface of the conical housing, while the liquid migrates closer to the axis of rotation of the housing. A screw conveyor then scoops the solids which have accumulated on the inside surface of the housing toward a solids discharge port. The purified liquid, such as drilling mud, is discharged from the centrifuge at a liquids discharge port.
The sizes of the individual solid particles that are discharged from the solids discharge port fall within a wide range of diameters, but regardless of the sizes, these solid particles are abrasive as they pass over edges of the centrifuge discharge port. Over time, this abrasion requires maintenance on the centrifuge, which in the most severe cases may even call for the replacement of the conical housing.
In order to reduce the speed at which the abrasion of the discharge port occurs, known centrifuges include liners at the discharge ports. The discharge ports themselves are circular and the liners are inserted from the inside of the conical housing into the discharge port. The liners and the surface into which they are inserted are tapered, so that as the conical housing turns at high speed, the tapered liner presses more firmly into the circular opening of the discharge port.
Unfortunately, even the most wear resistant liner eventually erodes to the point that it no longer protects the discharge port. At this point, the liners in all of the discharge ports must be replaced. In most cases, this operation can only be performed by qualified personnel in a shop, and thus the centrifuge itself must be removed from its housing and shipped to a repair facility.
Once the centrifuge arrives at the repair facility, the conical housing must be removed in order for repair personnel to gain entry to the interior of the conical housing. Then, the eroded liners are removed and replaced with fresh ones. Finally, the refurbished conical housing is put back the centrifuge and the refurbished conical housing must then be balanced. If the conical housing is not properly balanced, then at 3,000 rpm the machine may generate unacceptable vibration or worse.
Thus, there remains a need for a device to protect the discharge ports of a horizontal, decanter centrifuge which will not require such an expensive and involved procedure as is current today in the art. The present invention is directed to filling this need in the art.